Tema 1:
Redes de acceso a Internet.
Estructura de Internet
 MPLS
Tecnologías cableadas




Digital Subscriber Line (xDSL)
Cable Broadband Service
Broadband Over Power Lines
Fiber
Tecnologías inalámbricas
 Satellite
 Wireless 3G
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010 – http://www.grc.upv.es/docencia/tra/
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
A “nuts and bolts” view of a network
 Millions of connected computing
devices: hosts, end-systems
 pc’s workstations, servers
 PDA’s phones, toasters
running network apps
 communication links
 fiber, copper, radio, satellite
router
server
mobile
local ISP
 routers: forward packets (chunks) of
data thru network
 protocols: control sending, receiving
of msgs
regional ISP
 TCP, IP, and HTTP, FTP, PPP, …
2
workstation
company
network
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
3
A closer look at the network structure
1. The network edge: applications
and hosts
2. The network core:
 routers
 network of networks
3. The access networks and
physical media: communication
links
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Internet structure: network of networks
 Roughly hierarchical
 National/international
backbone providers (NBPs)
 e.g. BBN/GTE, Sprint, AT&T,
IBM, UUNet
 interconnect (peer) with each
other privately, or at public
Network Access Point (NAPs)
 A point of presence (POP) is a
machine that is connected to
the Internet.
 Internet Service Providers
(ISPs) provide dial-up or direct
access to POPs.
 regional ISPs
 connect into NBPs
 local ISP, company
 connect into regional ISPs
4
local
ISP
regional ISP
NBP B
NAP
NAP
NBP A
regional ISP
local
ISP
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Network Access Points (NAPs)
Note: Peers in this context are
commercial backbones.
5
Source: Boardwatch.com
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
MCI/WorldCom/UUNET Global Backbone
6
Source: Boardwatch.com
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
7
The situation in Europe
See: http://www.redes.upv.es/ralir/en/MforS/GEANT2.WMV
Also: http://video.google.com/googleplayer.swf?docId=-4949195951027294198&hl=en-GB
More about technolgies: http://video.google.com/googleplayer.swf?docId=-4634094763983277329&hl=en-GB
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
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8
Hierarchical Routing
 aggregate routers into regions, “autonomous systems”
(AS)
 routers in same AS run same routing protocol
 “intra-AS” routing protocol
 routers in different AS can run different intra-AS routing protocol
 Gateway router
 Direct link to router in another AS
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Interconnected ASes
3c
3a
3b
AS3
2a
1c
1a
1d
1b AS1
Intra-AS
Routing
algorithm
Inter-AS
Routing
algorithm
Forwarding
table
2c
AS2
2b
 forwarding table
configured by both
intra- and inter-AS
routing algorithm
 intra-AS sets entries for
internal dests
 inter-AS & intra-As sets
entries for external dests
4-9
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
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1
0
Intra-AS Routing
 also known as Interior Gateway Protocols (IGP)
 most common Intra-AS routing protocols:
 RIP: Routing Information Protocol
 OSPF: Open Shortest Path First
 IGRP: Interior Gateway Routing Protocol (Cisco proprietary)
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
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1
1
Internet inter-AS routing: BGP
 BGP (Border Gateway Protocol): the de facto standard
 BGP provides each AS a means to:
 Obtain subnet reachability information from neighboring ASs.
 Propagate reachability information to all AS-internal routers.
 Determine “good” routes to subnets based on reachability
information and policy.
 allows subnet to advertise its existence to rest of
Internet: “I am here”
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Why MPLS?
 Integrate best of Layer 2 and
Layer 3
- Intelligence of IP Routing
- performance of high-speed
switching
- Legacy service transport
- QoS
- VPN Semantics
- Link layers include:
- Ethernet, PoS, ATM, FR
Note: MPLS and IP could be optimal solution for overall IP
Services Architecture.
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
MPLS as a Foundation for Value Added Services
VPNs
Traffic
Engineering
IP+ATM
IP+Optical
GMPLS
MPLS
Network Infrastructure
Any
Transport
Over MPLS
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
General Context
• At Edge (ingress):
Classify packets
Label them
(CE) – Customer Edge
• In Core:
Forward using labels (as
opposed to IP addr)
Label indicates service
class and destination
Edge Label
Switch Router
(PE) – Provider Edge
Label Switch
Router (LSR)
(P) – Provider
Label Distribution
Protocol (LDP/TDP,
RSVP,BGP)
• At Edge (egress):
Remove Label
(PE) – Provider Edge
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Control and Forward Plane Separation
RIB
Routing
Process
Route
Updates/
Adjacency
Control Plane
LIB
MPLS
Process
Label Bind
Updates/
Adjacency
Data Plane
LFIB
FIB
MPLS Traffic
IP Traffic
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
MPLS Example: Routing Information
In
Address
Label Prefix
Out
I’face
Out
Label
In
Address
Label Prefix
Out
I’face
128.89
1
128.89
0
171.69
1
171.69
1
…
…
…
…
Out
Label
In
Address
Label Prefix
Out
I’face
128.89
0
…
…
0
Out
Label
128.89
0
1
You Can Reach 128.89 Thru Me
You Can Reach 128.89 and
171.69 Thru Me
Routing Updates
(OSPF, EIGRP, …)
1
You Can Reach 171.69 Thru Me
171.69
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
MPLS Example: Assigning Labels
In
Address
Label Prefix
Out
I’face
Out
Label
In
Address
Label Prefix
Out
I’face
Out
Label
-
128.89
1
4
4
128.89
0
9
-
171.69
1
5
5
171.69
1
7
…
…
…
…
…
…
…
…
In
Address
Label Prefix
Out
I’face
Out
Label
9
128.89
0
-
…
…
…
…
0
0
1
Use Label 9 for 128.89
Use Label 4 for 128.89 and
Use Label 5 for 171.69
Label Distribution
Protocol (LDP)
(downstream allocation)
1
171.69
Use Label 7 for 171.69
128.89
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
MPLS Example: Forwarding Packets
In
Address
Label Prefix
Out
I’face
Out
Label
In
Address
Label Prefix
Out
I’face
Out
Label
-
128.89
1
4
4
128.89
0
9
-
171.69
1
5
5
171.69
1
7
…
…
…
…
…
…
…
…
128.89.25.4
Out
Label
128.89
0
-
…
…
…
…
0
128.89
0
1
4
Out
I’face
9
MPLS network
egress point
128.89.25.4
1
128.89.25.4 Data
In
Address
Label Prefix
Data
Label Switch Forwards
Based on Label
9
128.89.25.4
Data
Data
1
9
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Un ejemplo: ONO
2
0
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Un ejemplo: ONO
2
1
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Un ejemplo: ONO
Tecnologías cableadas de acceso
time
2010
2005
SHDSL
UDSL
HDSL
SDSL
VDSL
ADSL
GPRS
2B1Q
VoD
TV digital Voice
4B3T
1995 Power
line
ISDN
xDSL
POTS
TV analog
1980
Copper
TV
DECT
WLAN
EDGE
GSM
PDC
CDMA
VSAT
WLL
Satellite
Coax Wireless
BPON
HSCSD
PMP
2000
1990
UMTS
CDMA
STM 1
OPAL
Bluetooth
AMPS
PON
AON
Cellular radio
Fiber optics
1975
Copper
1900
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010 – http://www.grc.upv.es/docencia/tra/
2
3
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Implantación de las diversas tecnologías
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
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4
What is xDSL
 DSL: Digital Subscriber Line
 DSL as a transmission
technology using the existing
copper wires between a
central exchange and a
customer with a bit rate speed
up to 26 Mbit/s
 Signals:
symmetrical/asymmetrical,
digital, text, audio, video
 Concepts of local loop,
management, handshake,
interoperability, scalability,
legacy
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
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Why x-DSL
 Faster than analog (56 kbit/s) and ISDN (>128 kbit/s)
modems, reasonable cost, reach 3-6 km
 Less expensive that E1/T1 systems, 1.5-2.0- Mbit/s, reach 1
km
 Use already existing copper pairs (depending on the
performance): start as equipments installed.
 Transforms potential 700 millions copper wires installed worldwide
into multimegabit data pipes
 Scenario convenient to providers and users immediately
available
 Enable the management of different providers of different
services to different users tipology
 Alternative: Optical access
 Wait for full availability
 current cost
 better performance
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
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6
How it works
 Remove line components limiting the bandwidth to the
voice frequency (4 KHz = 64 Kbit/s)
 Use of copper low attenuation frequencies sending more
bits x Hertz for longer reach
 Use higher bit rate with a low increase of signal rate
(baud) in the line
 Use of line codes allowing the transmission of 2 to 15
bits x Hertz (up to 1.1, 2.2, 12 MHz)
 Adoption of techniques/phylosophies limiting negative
effects (crosstalk, echo, spectrum, etc.)
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Arquitectura de una red ADSL
192.76.100.7/25
VPI 18, VCI 23, PCR 256/128 Kb/s
VPI 18, VCI 31, PCR 512/256 Kb/s
192.76.100.1/25
192.76.100.12/25
Red ATM
Red
telefónica
192.76.100.15/25
DSLAM (ATU-C)
Internet
VPI 18, VCI 37, PCR 2048/300 Kb/s
Router-modem
ADSL (ATU-R)
Ethernet 10BASE-T
Bucle de abonado (conexión ADSL)
Enlace ATM OC-3 (155 Mb/s)
2
7
Circuito permanente ATM
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
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DSLAM Digital subscriber line access multiplexer
 A Digital Subscriber Line Access Multiplexer (DSLAM)
allows telephone lines to make faster connections to the
Internet.
 It is a network device, located near the customer's
location, that connects multiple customer Digital
Subscriber Lines (DSLs) to a high-speed Internet
backbone line using multiplexing techniques.
 By locating DSLAMs at locations remote to the telephone
company central office (CO), telephone companies are
now providing DSL service to consumers who previously
did not live close enough for the technology to work.
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
ADSL G.Lite (ITU G.992.2)
 ADSL requiere instalar en casa del usuario un filtro de
frecuencias o ‘splitter’ (teléfono de ADSL).
 El splitter aumenta el costo de instalación y limita el
desarrollo.
 ADSL G.Lite suprime el splitter. También se llama ADSL
Universal, ADSL ‘splitterless’ o CADSL (Consumer ADSL).
 Sin splitter hay más interferencias, sobre todo a altas
frecuencias.
3
0
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
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1
ADSL2 versus ADSL (G.992.3 x G.992.1)
 2nd generation of ADSL with improvements on:







Loop-reach increase for equivalent bit rates (300m)
Higher down/up bit rates
loop diagnostics
Adjustable spectrum shaping during operat/initializ
Power vs traffic control: L0(full),L1, L2
robustness against loop impairments and RFI
Improved multivendor interoperability
 Improved application support for an all digital mode of
operation and voice over ADSL operation;
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
ADSL 2+ : G.992.5
 Performance
 Increase downstream: to 16 Mbit/s
 Maybe increase in upstream (Oct. 2003)
 Increase reach (1.5 - 3 Km)
 ADSL+ doubles the bandwidth (from 1.1 to 2.2 MHz)
with a significant increase of data rates on short loops
 Backwards compatibility (needs G.992.3)
3
2
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
VDSL (Very high speed DSL)
 Es el ‘super-ADSL’. Permite capacidades muy grandes
en distancias muy cortas.
 Las distancias y caudales en sentido descendente
son:
 300 m
 1000 m
 1500 m
51,84 – 55,2 Mb/s
25,92 – 27,6 Mb/s
12,96 – 13,8 Mb/s
 En ascendente se barajan tres alternativas:
 1,6 – 2,3 Mb/s
 19,2 Mb/s
 Igual que en descendente (simétrico)
3
3
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Cable Broadband Service
 Developed for TV
distribution
 Evolved to provide
TV/Data/Voice
 Up to 15 Mbs
download;
2 Mbs upload
 Distance independent
 Register w/ FCC
3
4
Cable Modem
3
5
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Hybrid Fiber/Coax (HFC)
CATV Network
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Residential access networks: cable modems
3
6
Diagram: http://www.cabledatacomnews.com/cmic/diagram.html
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Gigabit Passive Optical Network (GPON) Fiber to
the Home Architecture
Central Office
Passive Outside Plant
Typically up to 20 km (28 dB)
Edge router
(data, video)
2.5 Gbps @ 1490 nm
Multi-dwelling units
splitters points
Small/medium
enterprises
1.2 Gbps @ 1310 nm
Optical
Line Terminal (OLT)
Softswitch
(for voice)
Optional 1,550 nm to
support local
analog/digital video if
required
Single family
homes
Optical
Network Terminal (ONT)
Source: Fiber to the Home Council
3
7
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
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Objetivos
 Soporte de todos los servicios: voz (TDM, tanto SONET
como SDH), Ethernet (10/100 BaseT), ATM,…
 Alcance máximo de 20 Km, aunque el estándar se ha
preparado para que pueda llegar hasta los 60 km.
 Soporte de varios bitrate con el mismo protocolo,
incluyendo velocidades simétricas de 622 Mb/s, 1.25
Gb/s, y asimétricas de 2.5 Gb/s en el enlace
descendente y 1.25 Gb/s en el ascendente.
 El número máximo de usuarios que pueden colgar de
una misma fibra es 64 (el sistema está preparado para
dar hasta 128).
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
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Futuro de GPON
 GPON no requiere de dispositivos electrónicos u optoelectrónicos activos para la conexión entre el abonado y
el operador, y por lo tanto supone una inversión y unos
costes de mantenimiento menores
 La mayoría de los grandes operadores actuales se han
decantado por la tecnología GPON.
 En 2007 muchas operadoras han realizado “pruebas
piloto” con pocos usuarios. El objetivo de estas pruebas
es empezar a vislumbrar las dificultades de trabajar la
fibra óptica.
 A lo largo de 2008 se espera el lanzamiento “masivo” de
servicios sobre GPON.
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Broadband Over Power Lines
High
Voltage
~ MVolts
Medium Voltage
~ 1kVolts to 40
kVolts
~ 120/240 Volts
Coupler
Power
Generatio
n
Plant
Substation
Backhaul
Point
(Gateway
)
Repeater
LV
Distribution
Transformer
Access BPL
Internet
4
0
Low Voltage
BPL signals are extracted here
& converted into/from traditional
communication packets for
appropriate communication direction
Aggregation
Point
Power Line
Interface
Device Located
In Home
In some Access
implementations,
these physical links
are replaced by
wireless links
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Tecnología PLC: Principios básicos
Una idea sencilla: Acondicionar la red eléctrica para la transmisión
simultánea de las señales de baja frecuencia (50/60 Hz) para transmisión
de energía y alta frecuencia (1-40 MHz) para transmisión de datos
Red de Acceso PLC
Conexión a otros
Principios básicos
Baja Tensión
(BT)
Media Tensión
(MT)
operadores
CT2
CT1
Termin
al
Punto
Interconexión
CT3
Repetidor
CT4
HE
100 – 300 hogares
HE: Equipo PLC en CT
CTn
4
1
CT5
CT6
Repetidor (Instalado en
el Cuarto de Contadores)
Terminal (Instalado en
Casa de Cliente)
CT: Centro de
Transformación MT/BT
 La Red Eléctrica es un medio
hostil para la transmisión de
datos: derivaciones, malas
conexiones, ruido, impedancia
variable...
 Modulaciones robustas: DSSS,
GMSK, OFDM
 No existe ningún estándar,
sino un grupo de sistemas
diferentes e incompatibles
entre sí
 Velocidades de transmisión de
hasta 200 Mbps compartidos
entre los usuarios, y
dependiendo de la
configuración
 Enchufe eléctrico (Toma única
de alimentación, voz y datos.)
 Permite seguir prestando el
suministro eléctrico sin ningún
problema
 Simetría del ancho de banda
El uso de la red eléctrica existente: La principal ventaja de la tecnología PLC
y su máximo condicionante
Ventajas
Atenuación
Attenuationvs.
vs Distance,
Distancia,PLC
cables
cables
PLC
120
30 MHz
a0 = 2e-3
110
a1 = 8e-6
k=0.5
100
a0
= 2e-3
A(f,d)
= e
a1 = 8e-6
k=0.5
90
Attenuation
Atenuación (dB)
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Tecnología PLC: Principios básicos
80
k
(a 0 a 1 f
1.6 MHz
10 MHz ( a a f
0
1
A(f,d)
=
20 MHz
e
70
60
k
10 MHz
)d
30 MHz
50
40
1.6 MHz
30
20
10
0
0
50
100
150
200
250
Distancia
Distance (meters)
(metros)
300
Permite gestión y control en Tiempo Real
Bi-direccional
Aprovecha la infraestructura eléctrica:
Alta disponibilidad (Red de MT mallada)
Mejora mantenimiento preventivo (medio físico
compartido)
 Rapidez de instalación
 Coste moderado
 Total independencia de:
• Obra Civil y licencias
• Licencias radio
• Interferencias
• Operadores TELCOM (Internos /
Externos)





20 MHz
)d
350
Desventajas
4
2
Densidad Espectral de Media Tensión




Variable en el tiempo
Ruido elevado
Altas atenuaciones
Múltiples reflexiones
Tecnologías inalámbricas de red
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010 – http://www.grc.upv.es/docencia/tra/
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Basics of Satellites
 Two Stations on Earth want to communicate through
radio broadcast but are too far away to use conventional
means.
 The two stations can use a satellite as a relay station for
their communication
 One Earth Station sends a transmission to the satellite.
This is called a Uplink.
 The satellite Transponder converts the signal and sends
it down to the second earth station. This is called a
Downlink.
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Basics: Advantages of Satellites
 The advantages of satellite communication over
terrestrial communication are:
 The coverage area of a satellite greatly exceeds that of a
terrestrial system.
 Transmission cost of a satellite is independent of the distance
from the center of the coverage area.
 Satellite to Satellite communication is very precise.
 Higher Bandwidths are available for use.
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Basics: Disadvantages of Satellites
 The disadvantages of satellite communication:
 Launching satellites into orbit is costly.
 Satellite bandwidth is gradually becoming used up.
 There is a larger propagation delay in satellite communication
than in terrestrial communication.
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Basics: How Satellites are used
 Service Types
 Fixed Service Satellites (FSS)
 Example: Point to Point Communication
 Broadcast Service Satellites (BSS)
 Example: Satellite Television/Radio
 Also called Direct Broadcast Service (DBS).
 Mobile Service Satellites (MSS)
 Example: Satellite Phones
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Types of Satellites
 Satellite Orbits





GEO
LEO
MEO
Molniya Orbit
HAPs
 Frequency Bands
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Geostationary Earth Orbit (GEO)
 These satellites are in orbit 35,863 km above the earth’s
surface along the equator.
 Objects in Geostationary orbit revolve around the earth at the
same speed as the earth rotates. This means GEO satellites
remain in the same position relative to the surface of earth.
 Advantages
 A GEO satellite’s distance from earth gives it a large coverage area,
almost a fourth of the earth’s surface.
 GEO satellites have a 24 hour view of a particular area.
 These factors make it ideal for satellite broadcast and other
multipoint applications.
 Disadvantages
 A GEO satellite’s distance also cause it to have both a comparatively
weak signal and a time delay in the signal, which is bad for point to
point communication.
 GEO satellites, centered above the equator, have difficulty
broadcasting signals to near polar regions
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Frequency Bands
 Different kinds of satellites use different frequency
bands.
L–Band: 1 to 2 GHz, used by MSS
S-Band: 2 to 4 GHz, used by MSS, NASA, deep space research
C-Band: 4 to 8 GHz, used by FSS
X-Band: 8 to 12.5 GHz, used by FSS and in terrestrial imaging,
ex: military and meteorological satellites
 Ku-Band: 12.5 to 18 GHz: used by FSS and BSS (DBS)
 K-Band: 18 to 26.5 GHz: used by FSS and BSS
 Ka-Band: 26.5 to 40 GHz: used by FSS
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
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TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
5
1
Satellite: an example
 Ofertas de Telefónica España
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
La llegada del 3G
Higher bandwidth
enables a range of new
applications!!
For the consumer
 Video streaming, TV
broadcast
 Video calls, video clips –
news, music, sports
 Enhanced gaming, chat,
location services…
For business
5
2
 High speed teleworking /
VPN access
 Sales force automation
 Video conferencing
 Real-time financial
information
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
GSM evolution to 3G
High Speed Circuit Switched Data
Dedicate up to 4 timeslots for data connection ~ 50
kbps
Good for real-time applications c.w. GPRS
Inefficient -> ties up resources, even when nothing
sent
Enhanced Data Rates for Global
Not as popular as GPRS (many skipping HSCSD)
GSM
Evolution
HSCSD
9.6kbps (one timeslot)
Uses 8PSK modulation
GSM Data
3x improvement in data rate on short
Also called CSD
distances
Can fall back to GMSK for greater distances
GSM
GPRS Combine with GPRS (EGPRS) ~ 384 kbps
Can also be combined with HSCSD WCDMA
General Packet Radio Services
Data rates up to ~ 115 kbps
EDGE
Max: 8 timeslots used as any one time
Packet switched; resources not tied up all the time
Contention based. Efficient, but variable delays
GSM / GPRS core network re-used by WCDMA (3G)
5
3
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
5
4
Quick Recap of 2G systems: Radio Interfaces
 Different in air interfaces
 Modulation and signaling
 eg- GSM 900
 Uplink: 890-915 MHz
 Downlink:
935-960
MHz
 25MHz -> 124 carrier
frequencies, spaced 200kHz
apart
 One or more frequencies
per base station
 ~270 kbps per carrier,
divided into 8 channels =
~33kbps per channel
AMPS
TACS
NMT
IS-54B
IS-136
GSM
IS-95
IS-95B
WCDMA
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
2G GSM – Core Network (Voice)
SCP
Um
BSC
A
TDM
ISUP/SS7
BTS
PSTN
HLR
AUC
VLR
EIR
SIM
Mobile Switching
Center (MSC)
Home Location
Register (HLR)
Visitor Location
Register (VLR)
Signaling System
No. 7 (SS7)
Phone switch plus:
mobile registration
call routing
inter MSC handovers
location updating
CDR creation
information of each
subscriber, type,
service
selected information
from the HLR for all
mobiles in MSC area
Packet signaling
network
Current location of
the subscriber
Often bundled with
MSC (VLR domain tied
in with MSC coverage)
SS7 to PSTN
5
5
Abis
Logically 1 HLR per
GSM network
Queries assigned HLR
AuC – Auth. center
EIR – Equip ID register
SCP – Service control point
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
2G GSM – Mobile Switching Center
MSC
Connects to the
fixed network (SS7)
BSC
Like a normal
PSTN/ISDN switch
with added mobile
functionality:
BSC
•Registration
BSC
•Authentication
•Location
updating
•Handovers
Depending on supplier, and design, urban or rural.
About 2-4 BSCs for each MSC
About MSC per 200K subscribers
Many variables
5
6
•Integrates
•Call
VLR
routing to
roaming sub…
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
5
7
GPRS…. What is it?
 General Packet Radio Service
 2.5G data service overlaid on an existing GSM network
 Mobile station uses up to 8 timeslots (channels) for GPRS data
connection from Mobile Station
 Timeslots are shared amongst users (and voice)
 Variable performance…




Packet Random Access, Packet Switched
Slotted Aloha Reservation / Contention handling
Throughput depends on coding scheme, # timeslots etc
From ~ 9 kbps min to max. of 171.8 kbps (in theory!)
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
GPRS: General Packet Radio Service
Circuit
Switched
Um
BTS
SIM
SCP
BSC
& PCU
Abis
TDM
A
PSTN
Packet
Switched
Core
FR
HLR
Gb
IP
Gn
Packet Control Unit
(PCU)
Serving GPRS Support Node
(SGSN)
Forward data frames from
TDM BSS to packet core
Packet transfer to, from serving area
New hardware in BSC
Registration, authentication, mobility
management / handover, CDRs
logical links to BTS, tunnel to GGSN
5
8
AUC
Gi
Internet
Corporate
Gateway GPRS Support
Node (GGSN)
Gateway to external IP
networks (VPN/ISP etc)
IP network security
GPRS session mgmt, AAAA
CDRs for charging
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
EDGE… also known as 2.75G
 EDGE Enhanced Data Rates for Global Evolution
 Uses 8-PSK modulation in good conditions
 Increase throughput by 3x
(8-PSK – 3 bits/symbol vs GMSK 1
bit/symbol)
 Fall back to GMSK modulation when far from the base station
 Combine with GPRS: EGPRS; up to ~ 473 Kbps. NB: GPRS &
EGPRS can share time slots
 New handsets / terminal equipment; additional
hardware in the BTS
 Core network and the rest remains the same
 TDMA (Time Division Multiple Access) frame structure
 200kHz carrier bandwidth allows cell plans to remain
 Initially no QoS; later GSM/EDGE Radio Access Network
(GERAN) QoS added
5
9
 EDGE access develops to connect to 3G core
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
6
0
3G Standards groups for UMTS/WCDMA
 3G development work has been driven by ETSI, UMTS
Forum
 WCDMA is the main 3G radio interface (driven initially by
DoCoMo)
 3GPP = 3G Partnership Program
 Produces specs for 3G system based on ETSI UTRA
(Universal Terrestrial Radio Access Interface)
 Also develops further enhancements for GSM/GPRS/EDGE
 Several org partners including ETSI, CWTS – China Wireless
Telecommunications Standards
 www.3gpp.org – eg- Juniper is an active member and
contributor
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Mobile Networks Evolution
Download
Speed
250-384 kbps
UMTS
90-180 kbps
40 kbps
1995
6
1
HSDPA
1-10 Mbps
EDGE
GPRS
2005
2015
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
3G = new network
GSM/GPRS
Radio network
2G SGSN
Packet switched
Core network
3G SGSN
GGSN
External IP
network
PCU
BSC
GSM
GPRS
UMTS/
HSDPA
HLR
UMTS/HSDPA
Radio network
RNC
2G MSC
3G MSC
GMSC
External
voice
network
6
2
Circuit switched
Core network
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
…and Beyond
 Technology Convergence on OFDM (Orthogonal
Frequency Division Multiple Access)
 WIMAX
 Standardized by IEEE 802.16, evolution of 802.11 (Wi-Fi)
 Improved bandwidth, encryption and coverage over WiFi
 Theoretical peak data rates of 70Mbps (practical peak ~2Mbps)
 Improved QoS better enables applications such as VoIP or IPTV
 Ideal application is for “last mile” connectivity to the home or
business
 Intel plans to embed WiMAX chips as part of ‘Intel Inside’
 L3GTE/HSOPA
6
3
 Early standardization work starts in 3GPP R8
 Improved bandwidth, latency over UMTS/HSxPA
 Radio technology based on MIMO-OFDM, peak data rates of up
to 70Mbps
 Network simplification
EV-DO  DO+, EV-DV  DV+
HSDPA  Enhanced UL (R6/R7)
Wide Area
Mobile
Cellular Industry
2G
2.5G
3G
4G Air
Interfaces
HSDPA
3.5G
Mobile
Broadband
TDD
Fixed
Wireless
Industry
802.16e
(Mobile)
Metro Area
Nomadic
Coverage/Mobility
TECNOLOGÍAS DE RED AVANZADAS – Master IC 2009-2010
Cellular/Fixed: Worlds Converge
802.16a/d
(Fixed
NLOS)
Local Area
Fixed
802.11n (smart antennas)
802.11 with Mesh extns.
802.16
(Fixed LOS)
802.11
b/a/g
Fixed Wireless Industry
Data Speeds (Kbps) span a wide range
6
4
10
100,000